As a rule, a processing apparatus for photographic material comprises several vessels each of which contains a treatment liquid, such as a developer, a fixer and a rinse liquid. The photographic material may be in the form of cut sheets, or in the form of a web unwound from a roll. The sheet material to be processed is transported through these vessels in turn, by transport means such as one or more pairs of drive rollers, and thereafter optionally to a drying unit.
Apparatus for the processing of photographic sheet material such as aluminium lithographic printing plates is known, for example from U.S. Pat. No. 5,455,651 (Verhoest et al./Agfa-Gevaert NV), comprising a plurality of treatment vessels. Each vessel comprises a sheet material inlet and a sheet material outlet to define a substantially horizontal sheet material path through the apparatus. The inlet and outlet are each closed by a pair of rotatable rollers biased into contact with each other to form a nip there-between through which the sheet material path extends. The rollers are used to remove excess treatment liquid from the sheet as it passes from one treatment vessel to the next. This reduces carry-over of treatment liquid and thereby reduces contamination and wastage. A good removal of processing liquid is also required to reduce the drying time of the sheet material after the last wet process step, and hence to reduce the energy use.
It is desirable that the treatment liquid in one vessel is not contaminated by contents of the adjacent vessels, that is neither by the treatment liquid of an adjacent vessel nor by vapours escaping from one vessel to another. Furthermore, in order to reduce consumption of treatment liquids, it is desirable to reduce the evaporation, oxidation and carbonisation thereof.
It has therefore been proposed to provide sealing means to seal each roller to the housing. By providing a gas- and liquid-tight seal between the rollers on the one hand and a wall of the housing on the other, treatment liquid in one vessel is not contaminated by the contents of adjacent vessels.
It has also been proposed to provide drip trays so positioned as to collect treatment liquid which escapes between a roller and its associated sealing means and drips from the roller. By collecting such escaping treatment liquid, contamination of adjacent vessels thereby is avoided, and more efficient operation can be achieved by recycling this escaped liquid.
Traditionally, an apparatus for processing photographic material has a horizontal configuration, i.e. the material path through the apparatus is substantially horizontal. However, processing machines having a substantially vertical orientation have also been proposed, in which the vessels have an opening at the top acting as a sheet material inlet and an opening at the bottom acting as a sheet material outlet or vice versa. The use of a vertical orientation for the apparatus leads to a number of advantages. In particular the apparatus occupies only a fraction of the floor space which is occupied by a conventional horizontal arrangement. Furthermore, the sheet transport path in a vertically oriented apparatus may be substantially straight, in contrast to the circuitous feed path which is usual in a horizontally oriented apparatus. The straight path is independent of the stiffness of the sheet material and reduces the risk of scratching compared with a horizontally oriented apparatus.
It would be desirable to be able to use the same apparatus, or parts of the same apparatus, for the processing of different photographic materials. Thus a modular construction is desirable, whereby at the choice of the user, a number of apparatus modules of differing function can be coupled together.
The choice between using a horizontal or a vertical apparatus is in part dependant upon the nature of the photographic material being processed and the opportunity for floor space reduction in integrated systems.
It would be advantageous for the user to be able to use one and the same apparatus module in both the vertical and horizontal configurations, substantially without significant modification. However, the modular constructions which have been proposed to date are suitable for use only in one orientation. It would also be desirable to enable a processing apparatus to be connectable to ancillary upstream or downstream equipment, such as laser recorders of various designs in order to best comply with the orientation demands of the integrated system so formed. In this connection, reference may be made to European patent application EP 0 744 652 (Agfa-Gevaert NV) which is concerned with an integrated apparatus in which an imaging element is fed automatically from an exposing part of the apparatus to a vertically oriented processing part.